A pathologist has cast doubt on an alleged killer’s claim he accidentally strangled a police officer during a sex game gone wrong.
Stefano Brizzi, 50, claimed he arranged to have sex with Pc Gordon Semple after they met through gay dating app Grindr.
He denies murdering the 59-year-old officer, but has admitted disposing of the body.
In a defence statement he claimed the pair watched pornography together before he placed a hood over Pc Semple's head at his request.
He said the officer asked him to tighten the leash as much as possible, and when it momentarily slipped, his neck "snapped", the Old Bailey heard.
He said he panicked afterwards when he discovered the dead man was a police officer and took steps to dispose of the body.
But Dr Benjamin Swift told jurors there was evidence that Pc Semple's death was not instant and that he had been strangled.
He said he found a fracture to a tiny horseshoe shaped bone in his neck as well as bruising and said it would have taken him minutes to die.
During that time, the victim may have suffered fits as a result of a lack of oxygen to the brain and "stiffening" of the muscles, he added.
He recorded the death as "unascertained" because Pc Semple's body had been dismembered and parts were never recovered.
The court heard he was presented with a number of plastic boxes containing body parts taken from Brizzi's flat as well as from the banks of the River Thames.
One piece had an area indicating a possible bite mark, and there was also evidence of "charring" and contact with acid, the court heard.
Sharp bladed tools, including a saw, as well as a blunt object were used to break up the head and body, jurors were told.
The officer's brain and most of the internal organs remain unaccounted for, the court heard.
The trial continues.
